In my opinion, Biochem 2EE3 is simply memorization but the course is definitely helpful as it gives you a solid foundation for many topics in biology and biochemistry. That being said, the material is quite heavy and sometimes you may be overwhelmed by the little details you need to remember for this course and the time required to study. I haven't taken Life Sci 3C03 so I cant comment on that but you should have a look at the course reviews to see if you can find something to help you with your decision.